The objective of this project is to develop a thin interfacial coating using RF plasma deposition techniques which will couple biological molecules to probes. The coating should allow attachment of molecular species in such a way that any conformational changes which occur will not interfere with, for example, specificity in bioassays. This project demands accurate and sensitive analysis of primary amine groups. Because of their importance in biology and medicine, effort is being invested in enhancing our abilities to measure these species by ESCA, static SIMS and chemical derivatization.